System and method to zero-sequence verify ground return path integrity by comparing measured zero-sequence current in an autotransformer with a second zero-sequence current source

摘要

A ground return path is determined to be impaired when no zero-sequence current is measured in the neutral return path, but zero-sequence current is detected in other suitable measuring points that include the windings of an autotransformer, or in a magnetically coupled delta-configured tertiary winding, or potential transformer.